Re: MW600 Firmware update possible?

It seems Sony has now discontinued the MW600 and re-released it as the MW600S, although there is no discernible difference between the two. This makes me wonder if the new model is simply running this upgraded firmware. If you try to go to the Sony website's product page for the MW600 (i.e. from a Google search), it comes up with a message saying "Sorry, the MW600 is no longer available." If the only difference is in the firmware, I think it should be incumbant upon Sony to release a tool that will allow owners of the MW600 to upgrade to the latest firmware as well.

Any feedback from Sony Support on this would be greatly appreciated.

UPDATE: It appears there is a difference in the headphones being packaged with the bluetooth receiver, or so it would appear from the pictures. However, the reciever itself still appears to be exactly the same, and the firmware argument still stands: if there is a firmware upgrade to be had, then it should be made available to all owners of the MW600.